NEET 2026 Mock Test Series (Day 4): Physics Mock Test with Answer Key & Detailed Solutions

NEET 2026 Mock Test Series Day 4 – Key Highlights

This Day 4 Physics mock test is specifically designed to improve your performance in one of NEET’s most challenging sections.

Includes:

• Physics-focused NEET practice questions

• NCERT-based conceptual and numerical problems

• Previous year trend-aligned questions

• Real NEET difficulty level simulation

• Same-day answer key and detailed solutions

Major Focus Areas:

• Mechanics

• Modern Physics

• Thermodynamics

• Current Electricity

• Electrostatics

• Magnetism

• Ray Optics

If Physics has been lowering your score in previous mock tests, Day 4 is where you start correcting those weaknesses systematically.

Day 4 Strategy: Strengthen Physics for Maximum Score Improvement

By Day 4, your NEET UG 2026 preparation should evolve from random practice to strategic score-building.

Your Goal: Improve Physics performance through targeted execution.

Recommended Attempt Strategy:

• Start before 10 AM for real exam simulation

• Solve easy and formula-based questions first

• Prioritise moderate conceptual problems second

• Leave lengthy numericals for the final round

• Avoid guesswork-heavy attempts

This structured strategy helps:

• Improve speed

• Increase accuracy

• Reduce negative marking

• Build confidence under pressure

Also Attempt Previous Mock Tests:

• NEET 2026 Mock Test Series Day 1

• NEET 2026 Mock Test Series Day 2

• NEET 2026 Mock Test Series Day 3

• NEET 2026 Mock Test Series (Day 1-10) Complete Plan

NEET 2026 Physics Mock Test Day 4 Question Paper

Instructions:

• Attempt all questions in a strictly timed environment

• Do not pause the test

• Avoid checking answers during the attempt

• Complete the full paper before reviewing solutions

• Focus on speed, precision, and concept application

Treat this as your real NEET exam simulation.

Physics

Q. 1

The damping force on an oscillator is directly proportional to the velocity. The units of the constant of proportionality are:

• A. kg m s⁻¹
• B. kg m s⁻²
• C. kg s⁻¹
• D. kg s

Q. 2

A combination of parallel plate capacitors is maintained at a certain potential difference. When a 3 mm thick slab is introduced between all the plates, in order to maintain the same potential difference, the distance between the plates is increased by 2.4 mm. Find the dielectric constant of the slab.

• A. 3
• B. 4
• C. 5
• D. 6

Q. 3

For a common emitter configuration, if $\alpha$ and $\beta$ have their usual meanings, the incorrect relationship between $\alpha$ and $\beta$ is:

• A. $\dfrac{1}{\alpha} = \dfrac{1}{\beta} + 1$
• B. $\alpha = \dfrac{\beta}{1 - \beta}$
• C. $\alpha = \dfrac{\beta}{1 + \beta}$
• D. $\alpha = \dfrac{\beta^{2}}{1 + \beta^{2}}$

Q. 4

When 2 kg of ice at 0 °C melts to water at 0 °C, the resulting change in its entropy, taking latent heat of ice to be 80 Cal/g, is:

• A. 586 cal/K
• B. 273 cal/K
• C. $8 \times 10^{4}$ cal/K
• D. 80 cal/K

Q. 5

A machine gun fires a bullet of mass 40 g with a velocity of 1200 m s⁻¹. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can he fire per second at the most?

• A. One
• B. Four
• C. Two
• D. Three

Q. 6

A water fountain on the ground sprinkles water all around it. If the speed of water coming out of the fountain is $v$, the total area around the fountain that gets wet is:

• A. $\pi\,\dfrac{v^{2}}{g}$
• B. $\pi\,\dfrac{v^{4}}{g^{2}}$
• C. $\dfrac{\pi}{2}\,\dfrac{v^{4}}{g^{2}}$
• D. $\pi\,\dfrac{v^{2}}{g^{2}}$

Q. 7

The dimensions of $(\mu_0\,\varepsilon_0)^{-\tfrac{1}{2}}$ are:

• A. $\left[L^{\tfrac{1}{2}}\,T^{-\tfrac{1}{2}}\right]$
• B. $\left[L\,T^{\tfrac{1}{2}}\right]$
• C. $\left[L\,T^{-1}\right]$
• D. $\left[L^{-\tfrac{1}{2}}\,T^{\tfrac{1}{2}}\right]$

Q. 8

A potentiometer circuit is set up as shown. The potential gradient across the potentiometer wire is $k$ volt/cm, and the ammeter reads 1.0 A when the two-way key is switched off. The balance points, when the key between terminals (i) 1 and 2, and (ii) 1 and 3 is plugged in, are found to be at lengths $l_1$ cm and $l_2$ cm respectively. The magnitudes of the resistors $R$ and $X$ in ohms are then:

• A. $k(l_1 - l_2)$ and $k\,l_2$
• B. $k\,l_1$ and $k(l_2 - l_1)$
• C. $k(l_2 - l_1)$ and $k\,l_1$
• D. $k\,l_1$ and $k\,l_2$

Q. 9

A dielectric slab of thickness $d$ is inserted in a parallel plate capacitor whose negative plate is at $x = 0$ and positive plate is at $x = 3d$. The slab is equidistant from the plates. The capacitor is given some charge. As one goes from $x = 0$ to $x = 3d$:

• A. The magnitude of the electric field remains the same
• B. The direction of the electric field remains the same
• C. The electric potential increases continuously
• D. Both (B) and (C)

Q. 10

The dielectric constant $k$ of an insulator cannot be:

• A. 3
• B. 6
• C. 8
• D. Infinity

Q. 11

Which one of the following gives the value of magnetic field due to a small current element according to Biot–Savart's law?

• A. $\dfrac{i\,\Delta l\,\sin\theta}{r^{2}}$
• B. $\dfrac{\mu_0}{4\pi}\cdot\dfrac{i\,\Delta l\,\sin\theta}{r}$
• C. $\dfrac{\mu_0}{4\pi}\cdot\dfrac{i\,\Delta l\,\sin\theta}{r^{2}}$
• D. $\dfrac{\mu_0}{4\pi}\cdot\dfrac{i\,\Delta l\,\sin\theta}{r^{3}}$

Q. 12

A conducting circular loop of radius $r$ carries a constant current $i$. It is placed in a uniform magnetic field $\vec{B}$ such that the plane of the loop is perpendicular to the magnetic field. The net magnetic force on it is:

• A. $i\,r\,\vec{B}$
• B. $2\pi\,i\,r\,\vec{B}$
• C. Zero
• D. $\pi\,r\,i\,\vec{B}$

Q. 13

The variation of the intensity of magnetisation ($I$) with respect to the magnetising field ($H$) in a diamagnetic substance is described by which graph?

• A. OD
• B. OC
• C. OB
• D. OA

Q. 14

In a cyclotron, the angular frequency of a charged particle is independent of:

• A. Mass
• B. Speed
• C. Charge
• D. Magnetic field

Q. 15

The magnetic field intensity for an axial point due to a short bar magnet of magnetic moment $M$ is given by:

• A. $\dfrac{\mu_0}{4\pi} \times \dfrac{M}{d^3}$
• B. $\dfrac{\mu_0}{4\pi} \times \dfrac{M}{d^2}$
• C. $\dfrac{\mu_0}{2\pi} \times \dfrac{M}{d^3}$
• D. $\dfrac{\mu_0}{2\pi} \times \dfrac{M}{d^2}$

Q. 16

Which of the following correctly represents the unit and dimension of electric current?

• A. Ampere & [AT]
• B. Ampere/sec & [AT²]
• C. Ampere & [A]
• D. None of the above

Q. 17

Which of the following is a scalar quantity?

• A. Magnetic field
• B. Electric field
• C. Magnetic flux
• D. None of the above

Q. 18

Calculate the reactance in the given circuit:

• A. $\pi$ $\Omega$
• B. $\dfrac{2}{\pi}$ $\Omega$
• C. $2\pi$ $\Omega$
• D. $\dfrac{1}{\pi}$ $\Omega$

Q. 19

A force of 100 N is just sufficient to pull a block of mass $10\sqrt{3}$ kg on a rough horizontal surface. What is the angle of friction? ($g = 10$ m/s²)

• A. 30°
• B. 45°
• C. 60°
• D. 50°

Q. 20

A particle is in straight-line motion with uniform velocity. A force is not required:

• A. To increase the speed
• B. To decrease the speed
• C. To keep the same speed
• D. To change the direction

Q. 21

Which of the following is incorrect for a perfectly reflecting surface? (where $a$ = absorptance, $t$ = transmittance, $r$ = reflectance)

• A. $a = 0$
• B. $t = 0$
• C. $r = 1$
• D. $a = 1$

Q. 22

If a bimetallic strip is heated, it will:

• A. Bend towards the metal with a lower thermal expansion coefficient
• B. Bend towards the metal with a higher thermal expansion coefficient
• C. Not bend at all
• D. Twist itself into a helix

Q. 23

A person of mass $M$ is standing in a lift. If the lift moves vertically upwards according to the given $v$–$t$ graph, find the apparent weight of the man at $t = 1$ s. ($g = 10$ m/s²)

• A. $20\,M$
• B. $10\,M$
• C. $5\,M$
• D. $15\,M$

Q. 24

$n$ moles of an ideal gas with constant-volume heat capacity $C_V$ undergo an isobaric expansion by a certain volume. The ratio of the work done in the process to the heat supplied is:

• A. $\dfrac{nR}{C_V + nR}$
• B. $\dfrac{nR}{C_V - nR}$
• C. $\dfrac{4nR}{C_V - nR}$
• D. $\dfrac{4nR}{C_V + nR}$

Q. 25

When an object is shot from the bottom of a long smooth inclined plane kept at an angle of 60° to the horizontal, it can travel a distance $x_1$ along the plane. But when the inclination is decreased to 30° and the same object is shot with the same speed, it can travel a distance $x_2$. Then $x_1 : x_2$ will be:

• A. $1 : \sqrt{2}$
• B. $\sqrt{2} : 1$
• C. $1 : \sqrt{3}$
• D. $1 : 2\sqrt{3}$

Q. 26

The compressibility factor $Z$ for a real gas can be:

• A. Less than 0
• B. Less than 1
• C. More than 1
• D. Both (B) and (C)

Q. 27

The maximum force acting on a body executing SHM is $F$ and the maximum energy of the body is $E$. The amplitude of the motion is:

• A. $\dfrac{E}{F}$
• B. $\dfrac{2E}{F}$
• C. $\dfrac{2F}{E}$
• D. $\dfrac{F}{2E}$

Q. 28

On which law is the principle of rocket propulsion based?

• A. Newton's First Law of Motion
• B. Newton's Law of Gravitation
• C. Newton's Third Law of Motion
• D. Law of Thermodynamics

Q. 29

The escape velocity from a planet can be calculated using:

• A. Its orbital velocity
• B. Its rotational speed
• C. Its mass and radius
• D. Its atmospheric pressure

Q. 30

What happens to the kinetic energy of a system in a perfectly inelastic collision?

• A. It remains the same
• B. It decreases
• C. It increases
• D. It becomes zero

Q. 31

If $\vec{a} + \vec{b} = \vec{c}$ and $a + b = c$, then the angle included between $\vec{a}$ and $\vec{b}$ is:

• A. 90°
• B. 180°
• C. 120°
• D. 0°

Q. 32

The angular acceleration of a body moving along the circumference of a circle is:

• A. Along the radius, away from the centre
• B. Along the radius towards the centre
• C. Along the tangent to its position
• D. Along the axis of rotation

Q. 33

A two-dimensional force is given by $\vec{F} = A(x\,\hat{j} + y\,\hat{i})$. The potential energy is:

• A. $Axy$
• B. $-Axy$
• C. $-2Axy$
• D. $2Axy$

Q. 34

Given a semi-circular disc of mass $M$ and radius $R$. Find its moment of inertia about an axis passing through its centre of mass (CM) and parallel to its diameter:

• A. $MR^{2}\!\left[\dfrac{1}{4}+\dfrac{16}{9\pi^{2}}\right]$
• B. $MR^{2}\!\left[\dfrac{1}{4}-\dfrac{16}{9\pi^{2}}\right]$
• C. $MR^{2}\!\left[\dfrac{1}{4}-\dfrac{8}{9\pi^{2}}\right]$
• D. $MR^{2}\!\left[\dfrac{1}{4}+\dfrac{9}{16\pi^{2}}\right]$

Q. 35

A circular ring is acted upon by a horizontal force $F$ at its centre and rolls on a horizontal surface without slipping. The acceleration of its centre of mass is:

• A. $\dfrac{2F}{M}$
• B. $\dfrac{F}{M}$
• C. $\dfrac{3F}{M}$
• D. $\dfrac{F}{2M}$

Q. 36

The differential scattering cross section is given by $D(\theta) = a^{2} + b^{2}\cos^{2}\theta$. If the intensity of the incoming particle beam is $I$, the intensity of the scattered particle beam is:

• A. $4\pi\!\left(a^{2}+\dfrac{b^{2}}{3}\right)$
• B. $4\pi\!\left(\dfrac{a^{2}+b^{2}}{3}\right)$
• C. $4\pi I\!\left(a^{2}+\dfrac{b^{2}}{3}\right)$
• D. $4\pi I\!\left(a^{2}-\dfrac{b^{2}}{3}\right)$

Q. 37

A radioactive sample $S_1$ having an activity of $5\,\mu\text{Ci}$ has twice the number of nuclei as another sample $S_2$ which has an activity of $10\,\mu\text{Ci}$. The half-lives of $S_1$ and $S_2$ can be:

• A. 20 years and 5 years
• B. $10^{4}$ years each
• C. 20 years and $10^{4}$ years
• D. 5 years each

Q. 38

A solenoid of inductance 100 mH and resistance 20 $\Omega$ is connected to a cell of emf 10 V. What is the energy stored in the inductor at time $t = 5\ln 2$ ms?

• A. $3.125 \times 10^{-3}$ J
• B. $4.25 \times 10^{-3}$ J
• C. $4.725 \times 10^{-3}$ J
• D. $5.15 \times 10^{-3}$ J

Q. 39

A planet has twice the density of Earth but the acceleration due to gravity on its surface is exactly the same as on the surface of Earth. Its radius in terms of the radius of the Earth $R$ will be:

• A. $R/4$
• B. $R/2$
• C. $R/3$
• D. $R/8$

Q. 40

A spherical planet far out in space has mass $M_0$ and diameter $D_0$. A particle of mass $m$ falling freely near the surface of this planet will experience an acceleration due to gravity equal to:

• A. $\dfrac{GM_0}{D_0^{2}}$
• B. $\dfrac{4GmM_0}{D_0^{2}}$
• C. $\dfrac{4GM_0}{D_0^{2}}$
• D. $\dfrac{GmM_0}{D_0^{2}}$

Q. 41

$F_g$ and $F_e$ represent the gravitational and electrostatic forces respectively between two electrons situated at a distance of 10 cm. The ratio $F_g/F_e$ is of the order of:

• A. $10^{43}$
• B. $10^{36}$
• C. $10^{-43}$
• D. $10^{-36}$

Q. 42

In the wave equation $Y = A\sin 2\pi\!\left(\dfrac{x}{a} - \dfrac{t}{b}\right)$, the speed of the wave is:

• A. $a/b$
• B. $b/a$
• C. $a$
• D. $b$

Q. 43

When X-rays of wavelength $0.5\,\text{Å}$ are transmitted through an aluminium slab of thickness 7 mm, the intensity reduces to one-fourth of the incident intensity. The attenuation coefficient of aluminium for these X-rays is:

• A. $0.188\,\text{mm}^{-1}$
• B. $0.189\,\text{mm}^{-1}$
• C. $0.198\,\text{mm}^{-1}$
• D. None of these

Q. 44

A fish in an aquarium approaches the left wall at a rate of 2.5 m/s and observes a fly approaching it at 8 m/s. If the refractive index of water is $\dfrac{4}{3}$, find the actual velocity of the fly.

• A. 2.5 m/s
• B. 3 m/s
• C. 3.5 m/s
• D. 3.75 m/s

Q. 45

Find the temperature at which oxygen molecules would have the same root-mean-square (rms) speed as hydrogen molecules at 300 K.

• A. 5400 K
• B. 4800 K
• C. 3200 K
• D. 1600 K

Smart Physics Time Management Strategy

Physics often becomes the deciding subject for rank improvement.

Best Time Allocation:

• Easy formula-based questions → First round

• Moderate conceptual questions → Second round

• Tough numerical problems → Final round

Key Rule:

Do not let difficult Physics questions drain your momentum early.

This approach improves:

• Question selection

• Speed efficiency

• Accuracy

• Final score stability

NEET 2026 Mock Test Day 4 Answer Key & Detailed Solutions

The NEET 2026 Mock Test Day 4 Physics answer key and detailed solutions have been updated after 5 PM on the same day, allowing you to evaluate your performance and identify critical mistakes immediately.

After checking your answers:

• Review incorrect responses carefully

• Analyse conceptual and numerical mistakes

• Identify weak chapters

• Revise formulas and key NCERT concepts

• Reattempt difficult questions for retention

This same-day correction cycle is highly effective in rapidly improving Physics performance before NEET 2026.

Day 4 Post-Test Revision Strategy

Your score improves most after analysis—not just practice.

Follow This High-Impact Revision Cycle:

• Immediately after test: Note all mistakes

• Within 2–3 hours: Analyse solutions deeply

• Evening: Calculate score and identify weak patterns

• Night: Revise NEET important formulas, concepts, and frequently missed chapters

This same-day strategy builds:

• Better retention

• Stronger conceptual clarity

• Faster performance growth

• More stable scores

Why Day 4 Physics Mock Test Matters

Physics is often the most difficult section for NEET aspirants and can significantly impact final rank.

Dedicated Physics practice helps:

• Strengthen problem-solving ability

• Improve numerical speed

• Reduce calculation errors

• Increase confidence

• Build subject mastery

Even a modest improvement in Physics can create a major boost in your total NEET score.

Day 4 Target: Stabilise and improve your Physics score.

Focus on:

• Better accuracy

• Faster solving

• Smarter attempts

• Lower negative marking

• Stronger chapter-wise confidence

By Day 4, your objective is not just practice—it is measurable score improvement.

Final Advice: Think Like a NEET Ranker

Top scorers do not simply revise more—they perform better under pressure.

Your Focus:

• Stay calm

• Trust your preparation

• Execute strategically

• Analyse deeply

• Improve daily

NEET success depends on:

Accuracy + Speed + Smart Decision-Making

Day 4 is your opportunity to make Physics a strength rather than a weakness.

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